#include<stdio.h>
#include<string.h>

int main()
{
	int sign,flag;
	char c[100]={'\0'};
	gets(c);
	int len=strlen(c);
	for(sign=0,flag=len-1;sign<=flag;sign++,flag--)
	{
		if(c[sign]!=c[flag]) break;
	}
	if(sign<=flag) printf("no");
	else printf("yes");
	return 0;
}
